db.Database.CreateChest C# (CSharp) Method

        public VaultChest CreateChest(Account acc)
        {
            MySqlCommand cmd = CreateQuery();
            cmd.CommandText = @"INSERT INTO vaults(accId, items) VALUES(@accId, '-1, -1, -1, -1, -1, -1, -1, -1');
            SELECT MAX(chestId) FROM vaults WHERE accId = @accId;";
            cmd.Parameters.AddWithValue("@accId", acc.AccountId);
            return new VaultChest
            {
                ChestId = (int)cmd.ExecuteScalar(),
                _Items = "-1, -1, -1, -1, -1, -1, -1, -1"
            };
        }

        protected override void HandleRequest()
        {
            StreamWriter wtr = new StreamWriter(Context.Response.OutputStream);
            if (Query.AllKeys.Length > 0)
            {
                using (Database db = new Database())
                {
                    Package package = Package.GetPackage(int.Parse(Query["packageId"]));

                    if (package == null)
                    {
                        wtr.Write("<Error>This package is not available any more</Error>");
                        return;
                    }

                    JsonSerializer s = new JsonSerializer();
                    var contents = s.Deserialize<PackageContent>(new JsonTextReader(new StringReader(package.Contents)));

                    Account acc = db.Verify(Query["guid"], Query["password"], Program.GameData);

                    if (CheckAccount(acc, db, false))
                    {
                        if (acc.Credits < package.Price)
                        {
                            wtr.Write("<Error>Not enough gold.<Error/>");
                            return;
                        }

                        var cmd = db.CreateQuery();

                        if (contents.items?.Count > 0)
                        {
                            foreach (var i in contents.items)
                            {
                                Dictionary<string, int> itemDic = new Dictionary<string, int>();
                                List<int> gifts = acc.Gifts;
                                gifts.Add(i);

                                cmd = db.CreateQuery();
                                cmd.CommandText =
                                    "UPDATE accounts SET gifts=@gifts WHERE uuid=@uuid AND password=SHA1(@password);";
                                cmd.Parameters.AddWithValue("@gifts", Utils.GetCommaSepString<int>(gifts.ToArray()));
                                cmd.Parameters.AddWithValue("@uuid", Query["guid"]);
                                cmd.Parameters.AddWithValue("@password", Query["password"]);
                                cmd.ExecuteNonQuery();
                            }
                        }

                        if (contents.charSlots > 0)
                        {
                            cmd = db.CreateQuery();
                            cmd.CommandText =
                                "UPDATE accounts SET maxCharSlot=maxCharSlot + @amount WHERE uuid=@uuid AND password=SHA1(@password);";
                            cmd.Parameters.AddWithValue("@amount", contents.charSlots);
                            cmd.Parameters.AddWithValue("@uuid", Query["guid"]);
                            cmd.Parameters.AddWithValue("@password", Query["password"]);
                            if (cmd.ExecuteNonQuery() == 0)
                                return;
                        }

                        if (contents.vaultChests > 0)
                        {
                            for (int j = 0; j < contents.vaultChests; j++)
                                db.CreateChest(acc);
                        }

                        db.UpdateCredit(acc, -package.Price);
                        wtr.Write("<Success/>");
                    }
                }
            }
        }